Lubricating apparatus



Nov. 27, 1934. E, w, DAvls LUBRICATING APPARATUS Filed Feb. 20, 1933 Non.

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' 55 plungerwhich takes VPatented Nov. 27, 1934 UNITED STATES Latinos' 'Lunroa'rlno4 APPARATUS Ernest W. Davis, Oak Park, lll., assigner, by

meme assignments, to Stewart-Warner Corporation, Chicago, Ill., a corporation of Virginia Application February zu, 1933, serial No. 551,491

s claims (c1. zzn-41.4)

My invention relates generallyto lubricating apparatus, and more particularly to improvements in pneumatically operated boosters for high pressure lubricating systems in which the coupling connection with the lubricant receiving iltting is made by pressure contact, as distinguished from a detachable mechanical interlocking connection. Y t

in using high pressures for the lubrication of lo machinery equipped with push type ilttings of the general construction illustrated in the patent to Oscar U. Zerk, No.'1,4'15,980, difficulty is encountered byA the operator in determining 'with what force it is necessary to press the l5 nozzle against the fitting. If the bearing does not offer any appreciable resistance, it is necessary to press the nozzle against the tting with only slight force, whereas when a bearing of high resistance is encountered, it is necessary 2o for the operator to press the nozzle against the ntting very tightly in order to overcome the back pressure of the lubricant and maintain the nozzle in sealing contact with the tting. 'The operator does not, however, have any way of determining whether a hearing about to be lubricated willioer a high resistance to the entrance of lubricant, or will permit the lubricant to ow freely into it.

To be assured that the nozzle will form an eiiective seal against the fitting under either condition above stated, the operator would have to apply the nomle to the fitting and forcefully maintain it in position with the expenditure of a great deal of muscular energy. The operation '35 of lubricating a machine is thereby rendered much more dicult and tiring tothe operator than necessary, since inthe lubrication 'of a 'large majority of the bearings of a' machine,

will now into the bearing quite the lubricant so readily and lit is not necessary'to apply the nozzle to the tting with a great deal of force.

if the operator assumes that s ,ll of the bearings to be lubricated are of low resistance, and therefore applies the nozzle tQ/'the ttings with a vrelatively slight pressurethe lubricant will leak rom the point of connection-of the nozzle and tting whenever a of high resistance is encountered. result is .a wastage of lubricant and soiling f the machine and greast()I ingpit or hoor. v

The above mentioned diillculties are encountered toa greater extent when utilizing a compressor of the type disclosed herein in which that portion of the discharge stroke of the place while the plunger is the plunger in its cylinder, is effected by the momentum of and its connected parts. The force of momentum isy effective to hold the nozzle against the tting during the lubricant discharging stroke of the plunger, but upon the 00 return stroke the force of the momentum of the plunger acts in the opposite direction and tends to pull the nozzle away from the tting. The latter force is substantially proportional to the air pressure acting upon the air piston connected to the plunger. l

In the compressor of my invention, means are provided automatically to cause the operator to push the nozzle against the lubricant receiving fitting with a force proportional tothe air pres- 7o s ure,A and thus assure theY maintenance of a sealed connection. The booster is so arranged that when a bearing of high resistance is encountered, the operator Vwill have topress the booster against the tting with a sufllciently high pressure to maintain theseal, in order to maintain the gun in operation. 1f he does not press the booster against the fitting with suflicient force to maintain the seal, the supply of air under pressure to the booster pump will be 30 cut of; v 'j It is thus the object of my invention to provide an improved lubricant compressor having means for making it necessary that the operator hold the compressor noule against a fitting g5 with sufficient force toprevent leakage between the nozzle and iitting. Y

A further object is to provide a pneumatically. operated lubricant compressor having meansfor interrupting the supply of compressed air to the motor of the gun whenever the nozzle of the gun is not held against the lubricant receiving ttng with sufficient force to maintain a lubricant-.tight seal therewith.

A further object is to provide' an improved 95 lubricant compressor having a motor and a handle for forcing the compressor nozzle against a lubricant receiving fitting, the handle being connected to the compressorrin such manner that the forces acting between the' compressor 100 and its handle are transmitted through an air cushion. e

A further object is to provide an improved pneumatically operated lubricant Vcompressor in which the force necessary to be'applied to hold y 105 the nozzle of the compressor in sealing contact with the lubricant receiving tting is proportionate tothe pressure of the compressed air Supply.

A further object is to provide an improved V lubricant compressor which may readily be converted into a booster.

A further object is to provide an. improved booster having means for aiding in priming the high pressure cylinder.

A further object is to provide an improved lubricant compressor which is simple in construction, may be easily operated, and which may be economically manufactured.

Other objects will appear from the following description, reference being had to the accompanying drawing, in which Fig. 1 is a central vertical sectional view of the grease gun shown as applied to a bear- Fig. 2 -is a vertical sectional view thereof taken on the line 2 2 of Fig. 1, and

Fig. 3 is a fragmentary section showing the changes necessary to convert a lubricant compressor of the type having a lubricant reservoir to one of the booster type.- i

The lubricant compressor comprises a body 10 having a grease reservoir barrel 12 threaded thereto. The barrel 12 is preferably provided 4with a cap 14 having a socket 16 formed on its inner surface to receive a tube i8. The lower end of the tube is provided with one or more apertures 20, while the upper end is threaded into a boss 22 formed on the body 10.

A check valve cage 24 is threaded into the up` per end of the tube 18 and is provided with a spring pressed ball check valve 26.y

A piston 28 is freely slidable in the barrel 12 upon the tube 18, and comprises a pair of oppositely facing cup leathers and reinforcing plates rigidly secured to a sleeve 30. The sleeve is provided with a suitable packing box packing and packing nut, to prevent leakage between it and the tube 18. Grease, or other lubricant, may be forced into the upper end of the barrel 12 through a passageway 32 formed in the body 10, by connecting a suitable source of lubricant under pressure to a pin tting 34 which is threaded in a boss 36 formed on the body 10, and communicates with the grease passageway 32.

The lubricant inthe barrel 12 is maintained under pressure, as will appear hereinafter, and

forced through a passageway 32 into the bore inlet port 42 formed therein. The cylinder 40 is secured in a bore 44 formed in the end of the body 10 by a nut 46 and lock nut 48. The end of the bore 38is' closed by a spring pressed discharge check valve 5 0. The end oi the cylinder is internally threaded to receive a nozzle extension 52, to the outer end of which a nozzle 54 is secured. The nozzle has a contact face 56 adapted to make a sealing contact with a lubricant receiving fitting 58 threaded in a bearing 60. A hose and suitable coupler may, of course, be substituted for the nozzle whenever desired.

A high pressure plunger 62 is reciprocable in the bore 38 of the cylinder 40, a seal to prevent leakage of lubricant past the plunger being formed by a hat washer 64 retained at the rearward end of the cylinder 40 by a cap nut 66.

The hat washer is preferably made of ilexible material, such as leather, and is pressed into engagement with. the'plunger 62 by a conical washer 68 held against the sealing washer 64 by la compression coil spring 70.

The rearward end of the plunger 62 has a head 72 secured thereto by a screw '14, the head being illustrated as being rigidly held in a socket Z6 formed in the end of an air motor piston 78 by a threaded ring 80. In many instances it will be desirable to provide a lost motion connection between the plunger 62 and the piston 78. The air motor piston '78 has a portion 82 of enlarged diameter which has a sliding fit in a bore 84 formed in the body 10, and a portion 86 of lesser diameter, which is slidable in a bore 88. The piston 7'8 has a central bore 90 which is open at its rearward end, and at its forward end is provided with a pair of ducts 92. The piston 78 is adapted to be moved under air pressure from the position in 'which it is shown in Fig. 1 to a position in which the greater part of the portion 86 of smaller diameter is projected into a chamber 94, which is in communication with the atmosphere through a port 96. The rearward end of the bore 84 is closed by a threaded plug 98, and air under pressure is supplied to the bore 84 at its forward end through an air passageway 100. The air passageway communicates with the bore 84 at a point beyond the plug 98 through a duct 102.

A handle supporting element 104 is threaded in the threaded end of the bore 84 and is pro,

vided with a shoulder 106 forming a seat for a valve '108. The valve 108 is rigidly secured to a valve stem 110, which is formed integrally with or rigidly securedto a handle plunger 112, which is freely slidable in a bore 114 formed in the handle supporting element 104. A cup leather 116 is provided to prevent leakage around the handle plunger 112. A handle 118 is threaded to the end of the plunger 112. Air under pressure is supplied to the space between the valve seat 106 and the end of the .plunger 112 through a fitting 120 threaded in the handie supporting member 104. The fitting may be of any suitable construction and is illustrated as an angle pin fitting of well known construction. Theball checkv valve is, however, preferably omitted from the iitting. An air 'hose 122, connected to a suitable source of compressed air, is connected to the tting 120 by a coupler 124 of conventional construction.

A manually operable needle valve ..126 is threaded in the body 10 and is adaptedgto permit venting of any air which may be erf in the high pressure cylinder.

The grease gun illustrated in Figs. 1 and 2 operates in the following manner: Assuming that the hose 122 is connected to the fitting 120 and supplied with air under suitable pressure, and assuming that'thlhe upper portion of the barrel 12 has been lled with lubricant, the operator will grasp the handle 118 and press the nozzle 56 against a lubricant receiving tting 58 at;- tached to the bearing 60 to be lubricated. The operator will have to press sumciently hard -against the handle 118 to overcome the pressure of the air exerted upon the cup leather 116 of the handle plunger 112, thus to open the valve 108 and permit the air under pressure to iiow into the passageway 100. Some of the air thus supplied to the passageway 100 will now past the check valve 26 through the tube 18 and apertures 20 into the lower end of the barrel 12, and y thus exert pressure upon the lower face of thev piston 28 and force the latter upwardly to cause suiiicient flow of lubricant through the passageway 32 into the bore 38 of the high pressure cylinder to prime the latter. If air is present in the passageway 32, such air may be vented ped f' As soon as the valve 108 is open, air will iiow into the bore 84 and thence through the ports 6 92intothebore90. Airpressurewillthusbe 'exerted upon the rear face of the air piston '18.

' greater force to and force the latter to theleft v(llig. 1), until the ports 92 are covered by the walls of the bore 88.' Thereafter,l the air piston will continue backward movement, due to its acquired momentum, until the ports 92 communicate with the air under atmospheric pressure inthe chamber 94, whereupon the pressure upon the rear face of the air piston is suddenly reduced. During the latter portion of theforward stroke of the air piston, after the ports 92 are closed by the walls of the-bore 88, air pressure exerted in the annular space surroundlngthe reduced por-V tion 78 of theair piston forms an effective cush. ion gradually to stop-the forward movement of the piston.

Thereafte the pressure within this annular space -and exerted upon the annular shoulder formed by the enlarged portion 82 of the piston forcesvthe air piston to the right, until the ports 92 again communicate `with the com air, whereupon the air rushes into the right hand end of the bore 86 and forms an air cushion to arrest the return movement of the air piston.

During the forward stroke of the air piston, the plunger 62 is advanced lin the bore 38 and forces the lubricant therein past the check valve 50 to the bearing. It will be noted'that the end of the plunger 62 passes the inlet port 42 after the ports 92 are in communication with the atmosphere 4and thus, during the portionof the stroke of the plunger 62which is eifective to discharge lubricant, the plunger derives its power solely from the momentum or inertia of the air piston and parts moving therewith, and that during this movement of the plunger it is being decelerated. As a result, a portion `of the inertia forces of the moving parts is transmitted to the nozzle 54 in a direction to hold the nozzle against lthe iitting. This fact, that the air motor itself provides a force to hold the nozzle against the fitting during the instant that lubricant is being discharged to the fitting, is very advantageous, since it makes it necessary for the .operatorjto vexert only sumcient force upon the handle to maintain the nozzle in con-f tact with the fitting, vand the additional force necessary to overcome-the back pressure of the lubricant is provided by the inertia of the air piston.

As the air piston approaches the end of'its return stroke, its momentum, of. course, exerts a force tending to move the nozzle away from.

the fitting and thus reactsagainst the manual force applied by the operator to hold the nozzle against the iitting. When thepressure of the compressed air supply is high, the operate more rapidly and with greater power, an'd it will be necessary manually to apply a the handle 118 to hold the nozzle against the fitting. It will be noted, how--l ever, that when the pressure of theair supply is high, a greater force will be required' toopen the valve 108 and'thus the operator will automatically .be req ed to exert a greater force upon the handle ,w n the pressure oi" the air supply is high. When the barrel 12 hasbeen emptied, a fresh supply of lubricant may readily be forced thereinto by connecting a source of lubricantunder pressure tothepin iitting 34.

air motor will- Ihe air control4 valve 118 has the pronounced advantage that it is automatically closed except when the nozzle is pressed against a ntting. Should the 'nozzle slip from a fitting, the air valve will automatically be closed and wastage o! lubricant prevented.

If it is desired to use the lubricant compressor above describedas a booster, this may readily be accomplished by removing the barrel 12 and the tube 18 and substituting therefor threaded booster, as modiiled by the changes illustrated in Fig. 3, the grease supply hose may be coupled directlyV to the iitting 34 and lubricant will flow directly therefrom through the passageway 32 to the high ypressure cylinder. Lubricant will, however, also iiow rearwardly .into the pressure chamber 132, and force the piston 134 downwardly, compressing the spring 138. Since' the plunger 62 reciprocates very rapidly, it is essential that the lubricant iiow very rapidly into the high pressure cylinder. The grease in a relatively long grease Supply hose might, due to its inertia andH due to its friction with the walls of the hose, fail to iiow sufliciently rapidly to prime the high pressure cylinder. With the pressure chamber 132, the lubricant in the passageway 23 will'at all times be maintained under relatively high pressure by the spring 138 lacting upon the piston 134, so that the priming of the high pressure cylinder will take place rapidly. In other respects, the construction of the booster suggested in Fig. 3 may be similar to that shown in Figs. 1 and 2, and its operation will vlikewise be similar to the previously describedembodiment oi' my invention. While I have shown and described a particular embodiment of my,inventon, it will be apparent tothose skilled in the art that various modiiications in design and construction may be made without departing from lthe spirit of my invention.

What I claim as new and desire to secure by Letters Patent oi. the United States is:

When using the lubricant compressor as a` LJInY-lubricating apparatus of the class dev scribed, the combination of a high pressure cyl- -.inder and plunger, means to supply lubricant to said high pressure cylinder, a reciprocating air motor operably connected with said plunger, a source of air under pressure, a valve located between said source and said air motor, a handle for holding the gun againsta fitting to be. suppliedwith lubricant, a piston connected to said handle and expod to air under pressure, and an operating connection between said valve and said piston.

2. In a lubricant compressor, the combination of a' source of lubricant under pressure, a high pressure cylinder, a plunger reciprocable therein, a. reciprocatory motor connected to said rcylinder and plunger for operation of the latter, a valve for admitting air under pressure to said motor, a handle for supporting saidmotor and cylinder, said handle having -a part exposed to the presthe latter bymovement'of the-handle in a direction opposed to the air pressure on said part.

3. In a device of the class described, the combination of a lubricantcompressor having a nozzle adapted to make a sealed connection with a lubricant receiving tting by pressure contact, a reciprocatory air motor for operating said compressor, said air motor being arranged to have its reciprocatory part operate said plunger upon the eiective portion of its discharge stroke by acquired momentum, a valve for admitting air under pressure to said air motor, and means for opening said valve, said means comprising a movable handle for supporting the lubricant compressor and having a piston operatively associated therewith and exposed to the air under pressure supplied to said air motor.

4. In lubricating apparatus of the class de-l scribed, the combination of a uid pressure operated lubricant pumping mechanism, a handle movably connected to said mechanism, a source of pressure uid, a valve for controlling the iiow ofthe pressure :fluid to said mechanism, an operative connection between said handle and said valve, and a piston connected to said handle andl exposed to the pressure of iiuid from said source,

said piston being operative to move said and close said valve.

5. In a high pressure lubricating apparatijs1,

handlev lli@ 

